Question

The books (whose) he used to help me were his old school books

Answer 1

Ответ:

Thebooks which he used to help me were his old school books.

Объяснение:

Answer 2

In the sentence you provided, "whose" is a relative pronoun used to indicate possession or association. It refers to the books that were used to help you. Here's the revised sentence with the necessary changes:

"The books that he used to help me were his old school books."